Question

Acceleration of block $A$ varies with time as shown in figure the value of coefficient of kinetic friction between $A$ and $B$ is
the value of coefficient of kinetic friction between block $A$ and $B$ is

Answer 1

Given the acceleration of limiting friction($f_l$) is 4.9m$s^{-2}$

$\therefore$ a=4.9m$s^{-2}$

The frictional force acting on A is${\mu }_{k}mg$

acceleration due to it$⟹$a=$\frac{{\mu }_{k}mg}{m}$

=${\mu }_{k}g$

$⟹$${\mu }_k$=$\frac{a}{g}$

=$\frac{4.9}{9.8}$=0.5